What is the Difference Between Nikon DX and FX Lenses?

Nikon FX and DX lenses refer to the format of image sensors on which the lenses are intended to operate. Nikon makes DSLRs with these two types of sensor formats (FX and DX) – also referred to as full frame and APS-C (or, crop sensor), respectively.

Brief Explanation of Full Frame (FX) and APS-C (DX) Cameras

The full frame sensor is the larger of the two. It is the size of a 35mm film frame – 36mm x 24mm.

The Nikon DX (or, APS-C) sensor is smaller at 24mm x 16mm, which is also slightly larger than Canon’s APS-C format. The field of view (how much of a scene you can see through the viewfinder) is smaller when using the same lens on an APS-C format camera than it would be on a full frame camera.

Nikon DX cameras include the D300S and lower camera lines. At the time of publication, Nikon DSLRs with four numbers in the model number (e.g., D7100, D5300, D3200) are all DX format cameras. The Nikon D300S is the only current DX format camera with less than four numbers in the model number.

FX vs. DX Lenses

Unlike the Canon system Nikon FX and DX lenses can be used interchangeably on either FX or DX cameras. However, the general rule is that DX lenses are design for use with Nikon DX format cameras like the D7100.

On the other hand, FX format lenses are generally acceptable to use on either the Nikon FX or DX format cameras. The times when you might want to consider a DX lens over an FX lens for a DX format camera are when you consider wide angle options. Due to the crop factor discussed above, wide angle DX lenses are generally cheaper than equivalent wide angle FX lenses because of the design.

Due to the crop factor, the common kit lenses also look different in terms of price and focal lengths for each format. Kit lenses for DX cameras are typically lenses like the 18-55mm and 18-105mm lenses. Typical Nikon FX format “kit” lenses are considered 24-120mm and 24-70mm lenses.

Advanced users may prefer to spend more money on a higher quality FX format lens to use with a DX format camera due to the overall quality of glass in the lens; however, that is a discussion for another day.

DX Crop Mode on FX Format Cameras

As mentioned above, DX lenses can be used on Nikon FX cameras like the D4S and D810. This is possible thanks to Nikon’s smart inclusion of a feature called “DX Crop Mode.”

Essentially, DX Crop Mode avoids the heavy vignetting that we would otherwise experience when using a DX lens on an FX camera by only recording the image using a smaller section in the center of the sensor. Of course, this results in an image with a reduced resolution. However, when you consider the D810 has a 36MP FX sensor, the DX Crop Mode still provides a final image with 15.3MP resolution. Not a bad trade-off at all.

Benefits of DX Lenses

Nikon DX lenses are generally smaller and lighter than Nikon FX lenses because less glass and a smaller lens barrel is required to produce an equivalent field of view for a lens that goes on an DX camera, like the Nikon D5300 and D3200 lines, when compared to a full frame camera. Additionally, as mentioned above, the DX line of lenses are generally more affordable.

Should I Buy FX or DX Lenses?

Hopefully, you are now aware of which Nikon lenses are compatible with your camera. As to which lens you should buy, my suggestion is to buy the one that fits your needs. If you want an extremely wide angle lens for your Nikon D3200 or D7100, then you’ll need to look at the DX line of lenses for something like the Nikon 10-24mm f/3.5-4.5G ED DX lens, which will look like a 15-36mm lens on your camera. You can’t find a non-fisheye lens this wide in Nikon’s FX line up.

If you are worried that you might upgrade someday to a full frame camera, don’t. Quality DX lenses hold their resale value just fine. And, of course, your DX lenses will work on any Nikon FX camera that you buy in the future.

Buy the lens that fits your needs now. If that means you want a massive FX telephoto lens, then go ahead. If you upgrade to a full frame camera later, it will work fine as well.

Comments

Generally speaking most 50mm prime lenses are made for FX or full frame cameras, whichever brand. With a Nikon camera, except the 3000 series, 5000 series and a few others like the D-40 will work with the Nikon 50mm f1.8 which is referred to as a nifty 50. Its resolution is superb and on a DX camera it equates to a 75mm f1.8, therefore making it a good portrait lens, or general purpose. Mostly Nikon includes kit lenses of 18 – 55 and 55 – 200 AFS lenses which have a built in focus motor in the lens, so they will work with those cameras mentioned before, whereas the AF 50mm f1.8 lens will work with every other Nikon camera perfectly. I have a couple of D-90s and they have built in focus motors which is what you need to use any straight AF lenses. I was a Nikon film uses and had several Nikon lenses and bought a Nikon D5000 and a brilliant lens 10 – 200 AFS VRII which is Nikon’s amazing vibration reduction system. It’s a beautiful lens. I also bough a Nikon 70 – 300 FX IF VRII and that gives me a reach of 105 – 450 in DX. Great for wildlife!!

The crop factor effect applies to both DX and FX lenses. So, you are correct that the 18-55mm lens behaves like a 27-82.5mm lens would on a full frame camera.

We often see compact cameras with an “equivalent” focal length zoom range – like “24-100mm equivalent” when the actual lens optics are 6-25mm. But camera and lens manufacturers don’t do that in the current lines of crop sensor cameras. As a result, you still need to take the crop factor lenses into account for DX lenses.

So, if I am understanding correctly, my N60 35mm camera with Tamrons 28-80mm and 75-300mm lenses are full frame(fx) format? I want to upgrade to a digital camera. Will these lenses work on a new DSLR camera? Any suggestions? Family photos, vacations, and kids sports pics.

What is your take on this set? I know that the lenses that come with it are not going to be the best. Probably very cheap.
I want to take fast sports pictures of our kids who play Soccer and Football. Do you think this kit will do the job? Or should I upgrade to the big brother D500 and look for a more expensive lens? Most of the time games start off with sun and then the sun sets and it’s only stadium lights we have. Just so you have an idea of the setting.

Go with the D7500. You’ll need a better telephoto lens eventually but that kit is a good starter kit.

The problem is the lower light levels. Try your 70-300mm but understand that the f/6.3 aperture is not bright enough for great action shots in low light. Eventually, look for 70-200mm f/2.8 options from Nikon, Sigma and Tamron depending on your budget.

Understand why your gear isn’t delivering the shot you want before you upgrade to more expensive gear though.

The 50mm f/1.8G lens is FX format, so it will provide a full FX image size at 50mm. The other lenses are DX lenses. You can use them in DX mode on the D750 just fine (1.5x crop). They’ll work basically like they do on your D5200. The image resolution will be 10.7MP, I believe.

Hi I realise you’ve probably been asked this millions of times so I’m sorry to ask again,
I have a D3300 with 18-55mm G VR AF-P DX lens and I’m looking to upgrade to a full frame
Nikon like the D750.Will this lens be suitable for this camera to make use of the full frame sensor,
or will I need to buy FX lenses?
Thanks.